872 lines
23 KiB
C
872 lines
23 KiB
C
/*
|
|
* Copyright (c) 1985, 1989, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
/*
|
|
* Portions Copyright (c) 1993 by Digital Equipment Corporation.
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies, and that
|
|
* the name of Digital Equipment Corporation not be used in advertising or
|
|
* publicity pertaining to distribution of the document or software without
|
|
* specific, written prior permission.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
|
|
* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
|
|
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
|
|
* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
|
|
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
|
|
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
|
|
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
|
|
* SOFTWARE.
|
|
*/
|
|
|
|
/*
|
|
* Portions Copyright (c) 1996-2001 by Internet Software Consortium.
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
|
|
* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
|
|
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
|
|
* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
|
|
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
|
|
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
|
|
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
|
|
* SOFTWARE.
|
|
*/
|
|
|
|
#if defined(LIBC_SCCS) && !defined(lint)
|
|
static const char sccsid[] = "@(#)res_send.c 8.1 (Berkeley) 6/4/93";
|
|
static const char rcsid[] = "$Id: res_send.c,v 1.7.2.1 2002/11/03 04:34:24 dhankins Exp $";
|
|
#endif /* LIBC_SCCS and not lint */
|
|
|
|
/* Rename the I/O functions in case we're tracing. */
|
|
#define send trace_mr_send
|
|
#define recvfrom trace_mr_recvfrom
|
|
#define read trace_mr_read
|
|
#define connect trace_mr_connect
|
|
#define socket trace_mr_socket
|
|
#define bind trace_mr_bind
|
|
#define close trace_mr_close
|
|
#define select trace_mr_select
|
|
#define time trace_mr_time
|
|
|
|
/*
|
|
* Send query to name server and wait for reply.
|
|
*/
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/param.h>
|
|
#include <sys/time.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/uio.h>
|
|
|
|
#include <netinet/in.h>
|
|
#include <arpa/inet.h>
|
|
|
|
#include <errno.h>
|
|
#include <netdb.h>
|
|
#include <signal.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
#include "minires/minires.h"
|
|
#include "arpa/nameser.h"
|
|
|
|
#define CHECK_SRVR_ADDR
|
|
|
|
static int cmpsock(struct sockaddr_in *a1, struct sockaddr_in *a2);
|
|
void res_pquery(const res_state, const u_char *, int, FILE *);
|
|
|
|
/* int
|
|
* res_isourserver(ina)
|
|
* looks up "ina" in _res.ns_addr_list[]
|
|
* returns:
|
|
* 0 : not found
|
|
* >0 : found
|
|
* author:
|
|
* paul vixie, 29may94
|
|
*/
|
|
int
|
|
res_ourserver_p(const res_state statp, const struct sockaddr_in *inp) {
|
|
struct sockaddr_in ina;
|
|
int ns;
|
|
|
|
ina = *inp;
|
|
for (ns = 0; ns < statp->nscount; ns++) {
|
|
const struct sockaddr_in *srv = &statp->nsaddr_list[ns];
|
|
|
|
if (srv->sin_family == ina.sin_family &&
|
|
srv->sin_port == ina.sin_port &&
|
|
(srv->sin_addr.s_addr == INADDR_ANY ||
|
|
srv->sin_addr.s_addr == ina.sin_addr.s_addr))
|
|
return (1);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/* int
|
|
* res_nameinquery(name, type, class, buf, eom)
|
|
* look for (name,type,class) in the query section of packet (buf,eom)
|
|
* requires:
|
|
* buf + HFIXEDSZ <= eom
|
|
* returns:
|
|
* -1 : format error
|
|
* 0 : not found
|
|
* >0 : found
|
|
* author:
|
|
* paul vixie, 29may94
|
|
*/
|
|
int
|
|
res_nameinquery(const char *name, int type, int class,
|
|
const u_char *buf, const u_char *eom)
|
|
{
|
|
const u_char *cp = buf + HFIXEDSZ;
|
|
int qdcount = ntohs(((const HEADER *)buf)->qdcount);
|
|
|
|
while (qdcount-- > 0) {
|
|
char tname[MAXDNAME+1];
|
|
int n, ttype, tclass;
|
|
|
|
n = dn_expand(buf, eom, cp, tname, sizeof tname);
|
|
if (n < 0)
|
|
return (-1);
|
|
cp += n;
|
|
if (cp + 2 * INT16SZ > eom)
|
|
return (-1);
|
|
ttype = getUShort(cp); cp += INT16SZ;
|
|
tclass = getUShort(cp); cp += INT16SZ;
|
|
if (ttype == type && tclass == class &&
|
|
ns_samename(tname, name) == 1)
|
|
return (1);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/* int
|
|
* res_queriesmatch(buf1, eom1, buf2, eom2)
|
|
* is there a 1:1 mapping of (name,type,class)
|
|
* in (buf1,eom1) and (buf2,eom2)?
|
|
* returns:
|
|
* -1 : format error
|
|
* 0 : not a 1:1 mapping
|
|
* >0 : is a 1:1 mapping
|
|
* author:
|
|
* paul vixie, 29may94
|
|
*/
|
|
int
|
|
res_queriesmatch(const u_char *buf1, const u_char *eom1,
|
|
const u_char *buf2, const u_char *eom2)
|
|
{
|
|
const u_char *cp = buf1 + HFIXEDSZ;
|
|
int qdcount = ntohs(((const HEADER *)buf1)->qdcount);
|
|
|
|
if (buf1 + HFIXEDSZ > eom1 || buf2 + HFIXEDSZ > eom2)
|
|
return (-1);
|
|
|
|
/*
|
|
* Only header section present in replies to
|
|
* dynamic update packets.
|
|
*/
|
|
if ( (((const HEADER *)buf1)->opcode == ns_o_update) &&
|
|
(((const HEADER *)buf2)->opcode == ns_o_update) )
|
|
return (1);
|
|
|
|
if (qdcount != ntohs(((const HEADER*)buf2)->qdcount))
|
|
return (0);
|
|
while (qdcount-- > 0) {
|
|
char tname[MAXDNAME+1];
|
|
int n, ttype, tclass;
|
|
|
|
n = dn_expand(buf1, eom1, cp, tname, sizeof tname);
|
|
if (n < 0)
|
|
return (-1);
|
|
cp += n;
|
|
if (cp + 2 * INT16SZ > eom1)
|
|
return (-1);
|
|
ttype = getUShort(cp); cp += INT16SZ;
|
|
tclass = getUShort(cp); cp += INT16SZ;
|
|
if (!res_nameinquery(tname, ttype, tclass, buf2, eom2))
|
|
return (0);
|
|
}
|
|
return (1);
|
|
}
|
|
|
|
isc_result_t
|
|
res_nsend(res_state statp,
|
|
double *buf, unsigned buflen,
|
|
double *ans, unsigned anssiz, unsigned *ansret)
|
|
{
|
|
HEADER *hp = (HEADER *) buf;
|
|
HEADER *anhp = (HEADER *) ans;
|
|
int gotsomewhere, connreset, terrno, try, v_circuit, resplen, ns, n;
|
|
u_int badns; /* XXX NSMAX can't exceed #/bits in this variable */
|
|
static int highestFD = FD_SETSIZE - 1;
|
|
|
|
if (anssiz < HFIXEDSZ) {
|
|
return ISC_R_INVALIDARG;
|
|
}
|
|
DprintQ((statp->options & RES_DEBUG) ||
|
|
(statp->pfcode & RES_PRF_QUERY),
|
|
(stdout, ";; res_send()\n"), buf, buflen);
|
|
v_circuit = (statp->options & RES_USEVC) || buflen > PACKETSZ;
|
|
gotsomewhere = 0;
|
|
connreset = 0;
|
|
terrno = ISC_R_TIMEDOUT;
|
|
badns = 0;
|
|
|
|
/*
|
|
* Some callers want to even out the load on their resolver list.
|
|
*/
|
|
if (statp->nscount > 0 && (statp->options & RES_ROTATE) != 0) {
|
|
struct sockaddr_in ina;
|
|
int lastns = statp->nscount - 1;
|
|
|
|
ina = statp->nsaddr_list[0];
|
|
for (ns = 0; ns < lastns; ns++)
|
|
statp->nsaddr_list[ns] = statp->nsaddr_list[ns + 1];
|
|
statp->nsaddr_list[lastns] = ina;
|
|
}
|
|
|
|
#if defined (TRACING)
|
|
trace_mr_statp_setup (statp);
|
|
#endif
|
|
|
|
/*
|
|
* Send request, RETRY times, or until successful
|
|
*/
|
|
for (try = 0; try < statp->retry; try++) {
|
|
for (ns = 0; ns < statp->nscount; ns++) {
|
|
struct sockaddr_in *nsap = &statp->nsaddr_list[ns];
|
|
same_ns:
|
|
if (badns & (1 << ns)) {
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
|
|
if (statp->qhook) {
|
|
int done = 0, loops = 0;
|
|
|
|
do {
|
|
res_sendhookact act;
|
|
|
|
act = (*statp->qhook)(&nsap, &buf, &buflen,
|
|
ans, anssiz, &resplen);
|
|
switch (act) {
|
|
case res_goahead:
|
|
done = 1;
|
|
break;
|
|
case res_nextns:
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
case res_done:
|
|
return (resplen);
|
|
case res_modified:
|
|
/* give the hook another try */
|
|
if (++loops < 42) /*doug adams*/
|
|
break;
|
|
/*FALLTHROUGH*/
|
|
case res_error:
|
|
/*FALLTHROUGH*/
|
|
default:
|
|
return ISC_R_UNEXPECTED;
|
|
}
|
|
} while (!done);
|
|
}
|
|
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; Querying server (# %d) address = %s\n",
|
|
ns + 1, inet_ntoa(nsap->sin_addr)));
|
|
|
|
if (v_circuit) {
|
|
int truncated;
|
|
struct iovec iov[2];
|
|
u_short len;
|
|
u_char *cp;
|
|
|
|
/* Use VC; at most one attempt per server. */
|
|
try = statp->retry;
|
|
truncated = 0;
|
|
|
|
/* Are we still talking to whom we want to talk to? */
|
|
if (statp->_sock >= 0 &&
|
|
(statp->_flags & RES_F_VC) != 0) {
|
|
struct sockaddr_in peer;
|
|
SOCKLEN_T size = sizeof(peer);
|
|
|
|
if (getpeername(statp->_sock,
|
|
(struct sockaddr *)&peer,
|
|
&size) < 0) {
|
|
res_nclose(statp);
|
|
statp->_flags &= ~RES_F_VC;
|
|
} else if (!cmpsock(&peer, nsap)) {
|
|
res_nclose(statp);
|
|
statp->_flags &= ~RES_F_VC;
|
|
}
|
|
}
|
|
|
|
if (statp->_sock < 0 ||
|
|
(statp->_flags & RES_F_VC) == 0) {
|
|
if (statp->_sock >= 0)
|
|
res_nclose(statp);
|
|
|
|
statp->_sock = socket(PF_INET,
|
|
SOCK_STREAM, 0);
|
|
if (statp->_sock < 0 ||
|
|
statp->_sock > highestFD) {
|
|
terrno = uerr2isc (errno);
|
|
Perror(statp, stderr,
|
|
"socket(vc)", errno);
|
|
return (-1);
|
|
}
|
|
errno = 0;
|
|
if (connect(statp->_sock,
|
|
(struct sockaddr *)nsap,
|
|
sizeof *nsap) < 0) {
|
|
terrno = uerr2isc (errno);
|
|
Aerror(statp, stderr, "connect/vc",
|
|
errno, *nsap);
|
|
badns |= (1 << ns);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
statp->_flags |= RES_F_VC;
|
|
}
|
|
/*
|
|
* Send length & message
|
|
*/
|
|
putUShort((u_char*)&len, buflen);
|
|
iov[0].iov_base = (caddr_t)&len;
|
|
iov[0].iov_len = INT16SZ;
|
|
iov[1].iov_base = (const caddr_t)buf;
|
|
iov[1].iov_len = buflen;
|
|
if (writev(statp->_sock, iov, 2) !=
|
|
(INT16SZ + buflen)) {
|
|
terrno = uerr2isc (errno);
|
|
Perror(statp, stderr, "write failed", errno);
|
|
badns |= (1 << ns);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
/*
|
|
* Receive length & response
|
|
*/
|
|
read_len:
|
|
cp = (u_char *)ans;
|
|
len = INT16SZ;
|
|
while ((n = read(statp->_sock,
|
|
(char *)cp, (unsigned)len)) > 0) {
|
|
cp += n;
|
|
if ((len -= n) <= 0)
|
|
break;
|
|
}
|
|
if (n <= 0) {
|
|
terrno = uerr2isc (errno);
|
|
Perror(statp, stderr, "read failed", errno);
|
|
res_nclose(statp);
|
|
/*
|
|
* A long running process might get its TCP
|
|
* connection reset if the remote server was
|
|
* restarted. Requery the server instead of
|
|
* trying a new one. When there is only one
|
|
* server, this means that a query might work
|
|
* instead of failing. We only allow one reset
|
|
* per query to prevent looping.
|
|
*/
|
|
if (terrno == ISC_R_CONNREFUSED &&
|
|
!connreset) {
|
|
connreset = 1;
|
|
res_nclose(statp);
|
|
goto same_ns;
|
|
}
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
resplen = getUShort ((unsigned char *)ans);
|
|
if (resplen > anssiz) {
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; response truncated\n")
|
|
);
|
|
truncated = 1;
|
|
len = anssiz;
|
|
} else
|
|
len = resplen;
|
|
if (len < HFIXEDSZ) {
|
|
/*
|
|
* Undersized message.
|
|
*/
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; undersized: %d\n", len));
|
|
terrno = ISC_R_NOSPACE;
|
|
badns |= (1 << ns);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
cp = (u_char *)ans;
|
|
while (len != 0 &&
|
|
(n = read(statp->_sock,
|
|
(char *)cp, (unsigned)len))
|
|
> 0) {
|
|
cp += n;
|
|
len -= n;
|
|
}
|
|
if (n <= 0) {
|
|
terrno = uerr2isc (errno);
|
|
Perror(statp, stderr, "read(vc)", errno);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
if (truncated) {
|
|
/*
|
|
* Flush rest of answer
|
|
* so connection stays in synch.
|
|
*/
|
|
anhp->tc = 1;
|
|
len = resplen - anssiz;
|
|
while (len != 0) {
|
|
char junk[PACKETSZ];
|
|
|
|
n = (len > sizeof(junk)
|
|
? sizeof(junk)
|
|
: len);
|
|
n = read(statp->_sock,
|
|
junk, (unsigned)n);
|
|
if (n > 0)
|
|
len -= n;
|
|
else
|
|
break;
|
|
}
|
|
}
|
|
/*
|
|
* The calling applicating has bailed out of
|
|
* a previous call and failed to arrange to have
|
|
* the circuit closed or the server has got
|
|
* itself confused. Anyway drop the packet and
|
|
* wait for the correct one.
|
|
*/
|
|
if (hp->id != anhp->id) {
|
|
DprintQ((statp->options & RES_DEBUG) ||
|
|
(statp->pfcode & RES_PRF_REPLY),
|
|
(stdout,
|
|
";; old answer (unexpected):\n"),
|
|
ans, (resplen>anssiz)?anssiz:resplen);
|
|
goto read_len;
|
|
}
|
|
} else {
|
|
/*
|
|
* Use datagrams.
|
|
*/
|
|
int start, timeout, finish;
|
|
fd_set dsmask;
|
|
struct sockaddr_in from;
|
|
SOCKLEN_T fromlen;
|
|
int seconds;
|
|
|
|
if (statp->_sock < 0 ||
|
|
(statp->_flags & RES_F_VC) != 0) {
|
|
if ((statp->_flags & RES_F_VC) != 0)
|
|
res_nclose(statp);
|
|
statp->_sock = socket(PF_INET, SOCK_DGRAM, 0);
|
|
if (statp->_sock < 0 ||
|
|
statp->_sock > highestFD) {
|
|
#ifndef CAN_RECONNECT
|
|
bad_dg_sock:
|
|
#endif
|
|
terrno = uerr2isc (errno);
|
|
Perror(statp, stderr,
|
|
"socket(dg)", errno);
|
|
return terrno;
|
|
}
|
|
statp->_flags &= ~RES_F_CONN;
|
|
}
|
|
#ifndef CANNOT_CONNECT_DGRAM
|
|
/*
|
|
* On a 4.3BSD+ machine (client and server,
|
|
* actually), sending to a nameserver datagram
|
|
* port with no nameserver will cause an
|
|
* ICMP port unreachable message to be returned.
|
|
* If our datagram socket is "connected" to the
|
|
* server, we get an ECONNREFUSED error on the next
|
|
* socket operation, and select returns if the
|
|
* error message is received. We can thus detect
|
|
* the absence of a nameserver without timing out.
|
|
* If we have sent queries to at least two servers,
|
|
* however, we don't want to remain connected,
|
|
* as we wish to receive answers from the first
|
|
* server to respond.
|
|
*/
|
|
if (statp->nscount == 1 || (try == 0 && ns == 0)) {
|
|
/*
|
|
* Connect only if we are sure we won't
|
|
* receive a response from another server.
|
|
*/
|
|
if ((statp->_flags & RES_F_CONN) == 0) {
|
|
if (connect(statp->_sock,
|
|
(struct sockaddr *)nsap,
|
|
sizeof *nsap) < 0) {
|
|
Aerror(statp, stderr,
|
|
"connect(dg)",
|
|
errno, *nsap);
|
|
badns |= (1 << ns);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
statp->_flags |= RES_F_CONN;
|
|
}
|
|
if (send(statp->_sock,
|
|
(const char*)buf, (unsigned)buflen, 0)
|
|
!= buflen) {
|
|
Perror(statp, stderr, "send", errno);
|
|
badns |= (1 << ns);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
} else {
|
|
/*
|
|
* Disconnect if we want to listen
|
|
* for responses from more than one server.
|
|
*/
|
|
if ((statp->_flags & RES_F_CONN) != 0) {
|
|
#ifdef CAN_RECONNECT
|
|
struct sockaddr_in no_addr;
|
|
|
|
no_addr.sin_family = AF_INET;
|
|
no_addr.sin_addr.s_addr = INADDR_ANY;
|
|
no_addr.sin_port = 0;
|
|
(void) connect(statp->_sock,
|
|
(struct sockaddr *)
|
|
&no_addr,
|
|
sizeof no_addr);
|
|
#else
|
|
struct sockaddr_in local_addr;
|
|
SOCKLEN_T len;
|
|
int result, s1;
|
|
|
|
len = sizeof(local_addr);
|
|
s1 = socket(PF_INET, SOCK_DGRAM, 0);
|
|
result = getsockname(statp->_sock,
|
|
(struct sockaddr *)&local_addr,
|
|
&len);
|
|
if (s1 < 0)
|
|
goto bad_dg_sock;
|
|
(void) dup2(s1, statp->_sock);
|
|
(void) close(s1);
|
|
if (result == 0) {
|
|
/*
|
|
* Attempt to rebind to old
|
|
* port. Note connected socket
|
|
* has an sin_addr set.
|
|
*/
|
|
local_addr.sin_addr.s_addr =
|
|
htonl(0);
|
|
(void)bind(statp->_sock,
|
|
(struct sockaddr *)
|
|
&local_addr,
|
|
(unsigned)len);
|
|
}
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; new DG socket\n"));
|
|
#endif /* CAN_RECONNECT */
|
|
statp->_flags &= ~RES_F_CONN;
|
|
errno = 0;
|
|
}
|
|
#endif /* !CANNOT_CONNECT_DGRAM */
|
|
if (sendto(statp->_sock,
|
|
(const char *)buf, buflen, 0,
|
|
(struct sockaddr *)nsap,
|
|
sizeof *nsap)
|
|
!= buflen) {
|
|
Aerror(statp, stderr, "sendto", errno, *nsap);
|
|
badns |= (1 << ns);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
#ifndef CANNOT_CONNECT_DGRAM
|
|
}
|
|
#endif /* !CANNOT_CONNECT_DGRAM */
|
|
|
|
if (statp->_sock < 0 || statp->_sock > highestFD) {
|
|
Perror(statp, stderr,
|
|
"fd out-of-bounds", EMFILE);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
|
|
/*
|
|
* Wait for reply
|
|
*/
|
|
seconds = (statp->retrans << try);
|
|
if (try > 0)
|
|
seconds /= statp->nscount;
|
|
if (seconds <= 0)
|
|
seconds = 1;
|
|
start = cur_time;
|
|
timeout = seconds;
|
|
finish = start + timeout;
|
|
wait:
|
|
FD_ZERO(&dsmask);
|
|
FD_SET(statp->_sock, &dsmask);
|
|
{
|
|
struct timeval t;
|
|
t.tv_sec = timeout;
|
|
t.tv_usec = 0;
|
|
n = select(statp->_sock + 1,
|
|
&dsmask, NULL, NULL, &t);
|
|
}
|
|
if (n == 0) {
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; timeout\n"));
|
|
gotsomewhere = 1;
|
|
goto next_ns;
|
|
}
|
|
if (n < 0) {
|
|
if (errno == EINTR) {
|
|
if (finish >= cur_time) {
|
|
timeout = finish - cur_time;
|
|
goto wait;
|
|
}
|
|
}
|
|
Perror(statp, stderr, "select", errno);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
errno = 0;
|
|
fromlen = sizeof(struct sockaddr_in);
|
|
resplen = recvfrom(statp->_sock,
|
|
(char *)ans, anssiz, 0,
|
|
(struct sockaddr *)&from, &fromlen);
|
|
if (resplen <= 0) {
|
|
Perror(statp, stderr, "recvfrom", errno);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
gotsomewhere = 1;
|
|
if (resplen < HFIXEDSZ) {
|
|
/*
|
|
* Undersized message.
|
|
*/
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; undersized: %d\n",
|
|
resplen));
|
|
terrno = ISC_R_NOSPACE;
|
|
badns |= (1 << ns);
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
}
|
|
if (hp->id != anhp->id) {
|
|
/*
|
|
* response from old query, ignore it.
|
|
* XXX - potential security hazard could
|
|
* be detected here.
|
|
*/
|
|
DprintQ((statp->options & RES_DEBUG) ||
|
|
(statp->pfcode & RES_PRF_REPLY),
|
|
(stdout, ";; old answer:\n"),
|
|
ans, (resplen>anssiz)?anssiz:resplen);
|
|
goto wait;
|
|
}
|
|
#ifdef CHECK_SRVR_ADDR
|
|
if (!(statp->options & RES_INSECURE1) &&
|
|
!res_ourserver_p(statp, &from)) {
|
|
/*
|
|
* response from wrong server? ignore it.
|
|
* XXX - potential security hazard could
|
|
* be detected here.
|
|
*/
|
|
DprintQ((statp->options & RES_DEBUG) ||
|
|
(statp->pfcode & RES_PRF_REPLY),
|
|
(stdout, ";; not our server:\n"),
|
|
ans, (resplen>anssiz)?anssiz:resplen);
|
|
goto wait;
|
|
}
|
|
#endif
|
|
if (!(statp->options & RES_INSECURE2) &&
|
|
!res_queriesmatch((u_char *)buf,
|
|
((u_char *)buf) + buflen,
|
|
(u_char *)ans,
|
|
((u_char *)ans) + anssiz)) {
|
|
/*
|
|
* response contains wrong query? ignore it.
|
|
* XXX - potential security hazard could
|
|
* be detected here.
|
|
*/
|
|
DprintQ((statp->options & RES_DEBUG) ||
|
|
(statp->pfcode & RES_PRF_REPLY),
|
|
(stdout, ";; wrong query name:\n"),
|
|
ans, (resplen>anssiz)?anssiz:resplen);
|
|
goto wait;
|
|
}
|
|
if (anhp->rcode == SERVFAIL ||
|
|
anhp->rcode == NOTIMP ||
|
|
anhp->rcode == REFUSED) {
|
|
DprintQ(statp->options & RES_DEBUG,
|
|
(stdout, "server rejected query:\n"),
|
|
ans, (resplen>anssiz)?anssiz:resplen);
|
|
badns |= (1 << ns);
|
|
res_nclose(statp);
|
|
/* don't retry if called from dig */
|
|
if (!statp->pfcode)
|
|
goto next_ns;
|
|
}
|
|
if (!(statp->options & RES_IGNTC) && anhp->tc) {
|
|
/*
|
|
* get rest of answer;
|
|
* use TCP with same server.
|
|
*/
|
|
Dprint(statp->options & RES_DEBUG,
|
|
(stdout, ";; truncated answer\n"));
|
|
v_circuit = 1;
|
|
res_nclose(statp);
|
|
goto same_ns;
|
|
}
|
|
} /*if vc/dg*/
|
|
Dprint((statp->options & RES_DEBUG) ||
|
|
((statp->pfcode & RES_PRF_REPLY) &&
|
|
(statp->pfcode & RES_PRF_HEAD1)),
|
|
(stdout, ";; got answer:\n"));
|
|
DprintQ((statp->options & RES_DEBUG) ||
|
|
(statp->pfcode & RES_PRF_REPLY),
|
|
(stdout, ""),
|
|
ans, (resplen>anssiz)?anssiz:resplen);
|
|
/*
|
|
* If using virtual circuits, we assume that the first server
|
|
* is preferred over the rest (i.e. it is on the local
|
|
* machine) and only keep that one open.
|
|
* If we have temporarily opened a virtual circuit,
|
|
* or if we haven't been asked to keep a socket open,
|
|
* close the socket.
|
|
*/
|
|
if ((v_circuit && (!(statp->options & RES_USEVC) || ns != 0)) ||
|
|
!(statp->options & RES_STAYOPEN)) {
|
|
res_nclose(statp);
|
|
}
|
|
if (statp->rhook) {
|
|
int done = 0, loops = 0;
|
|
|
|
do {
|
|
res_sendhookact act;
|
|
|
|
act = (*statp->rhook)(nsap, buf, buflen,
|
|
ans, anssiz, &resplen);
|
|
switch (act) {
|
|
case res_goahead:
|
|
case res_done:
|
|
done = 1;
|
|
break;
|
|
case res_nextns:
|
|
res_nclose(statp);
|
|
goto next_ns;
|
|
case res_modified:
|
|
/* give the hook another try */
|
|
if (++loops < 42) /*doug adams*/
|
|
break;
|
|
/*FALLTHROUGH*/
|
|
case res_error:
|
|
/*FALLTHROUGH*/
|
|
default:
|
|
return ISC_R_UNEXPECTED;
|
|
}
|
|
} while (!done);
|
|
|
|
}
|
|
*ansret = resplen;
|
|
return ISC_R_SUCCESS;
|
|
next_ns: ;
|
|
} /*foreach ns*/
|
|
} /*foreach retry*/
|
|
res_nclose(statp);
|
|
if (!v_circuit) {
|
|
if (!gotsomewhere)
|
|
terrno = ISC_R_CONNREFUSED; /* no nameservers found */
|
|
else
|
|
errno = ISC_R_TIMEDOUT; /* no answer obtained */
|
|
}
|
|
return terrno;
|
|
}
|
|
|
|
/*
|
|
* This routine is for closing the socket if a virtual circuit is used and
|
|
* the program wants to close it. This provides support for endhostent()
|
|
* which expects to close the socket.
|
|
*
|
|
* This routine is not expected to be user visible.
|
|
*/
|
|
void
|
|
res_nclose(res_state statp) {
|
|
if (statp->_sock >= 0) {
|
|
(void) close(statp->_sock);
|
|
statp->_sock = -1;
|
|
statp->_flags &= ~(RES_F_VC | RES_F_CONN);
|
|
}
|
|
}
|
|
|
|
/* Private */
|
|
static int
|
|
cmpsock(struct sockaddr_in *a1, struct sockaddr_in *a2) {
|
|
return ((a1->sin_family == a2->sin_family) &&
|
|
(a1->sin_port == a2->sin_port) &&
|
|
(a1->sin_addr.s_addr == a2->sin_addr.s_addr));
|
|
}
|
|
|
|
#ifdef NEED_PSELECT
|
|
/* XXX needs to move to the porting library. */
|
|
static int
|
|
pselect(int nfds, void *rfds, void *wfds, void *efds,
|
|
struct timespec *tsp,
|
|
const sigset_t *sigmask)
|
|
{
|
|
struct timeval tv, *tvp;
|
|
sigset_t sigs;
|
|
int n;
|
|
|
|
if (tsp) {
|
|
tvp = &tv;
|
|
tv = evTimeVal(*tsp);
|
|
} else
|
|
tvp = NULL;
|
|
if (sigmask)
|
|
sigprocmask(SIG_SETMASK, sigmask, &sigs);
|
|
n = select(nfds, rfds, wfds, efds, tvp);
|
|
if (sigmask)
|
|
sigprocmask(SIG_SETMASK, &sigs, NULL);
|
|
if (tsp)
|
|
*tsp = evTimeSpec(tv);
|
|
return (n);
|
|
}
|
|
#endif
|